1. Field
The present disclosure relates to wireless communication systems.
2. Background
Advances in technology have resulted in smaller and more powerful computing devices. For example, there currently exist a variety of portable personal computing devices, including wireless computing devices, such as portable wireless telephones, personal digital assistants (PDAs), and paging devices that are small, lightweight, and easily carried by users. More specifically, portable wireless telephones, such as cellular telephones and Internet Protocol (IP) telephones, can communicate voice and data packets over wireless networks. Many such wireless telephones incorporate additional devices to provide enhanced functionality for end users. For example, a wireless telephone can also include a digital still camera, a digital video camera, a digital recorder, and an audio file player. Also, such wireless telephones can execute software applications, such as a web browser application that can be used to access the Internet. As such, these wireless telephones can include significant computing capabilities.
A mobile communication device, such as User Equipment (UE) devices in wideband code division multiple access (WCDMA) systems, may report events to a wireless network. For example, mobile devices may report events based on fluctuations in strength of a received signal. Such reports may be made during hand-over and cell crossing scenarios. However, adverse radio reception conditions that trigger such reports may also degrade the mobile device's ability to decode responses from the network. For example, the network may instruct the mobile device to end an active link to a first cell and to create an active link to a second cell. If the reception conditions have deteriorated to the extent that the mobile device cannot decode the instructions, the mobile device may be unable to communicate via its assigned cell (the first cell) and may be unable to change cells. As a result, the mobile device may be dropped from the network.
In an effort to counter deteriorating network conditions, the mobile device may request that the network use more power in transmissions to the mobile device by increasing a signal-to-interference (SIR) target. Conventionally, mobile devices can increase the SIR target in response to failure to decode a message from the network. However, detecting a failure to decode a message introduces additional latency between an onset of degraded reception and an increase of the SIR target. When radio conditions deteriorate suddenly, such as during a fast cell crossing scenario, the ability of the mobile device to communicate with the network may be lost